Mischka



UNITED STATES PATENT OFFICE.

AUGUST H. PRINZ AND HERMANN HABER, OF VIENNA, EMERICH TOMISOHKA, OF I IIRSCHWANG, AND JOSEF FREIHERR VON BRENNER, OE VIENNA,

AUSTRIA-HUNGARY.

METHOD OF TREATING JUTE-BAST, 80G.

SPECIFICATION formingpart of Letters Patent No. 621,135, dated March 14, 1899.

Application filed December 31, 1897. SerialNo. 665,221. (No specimens.)

By way of example we shall in the following 15 description apply our process 'to the extraction of fibers from jute-hast, although we may in a similar manner extract fibers from chinagrass, rhea, and other vegetable matter.

In the mechanical treatment of the crude 2o jute-hast the sticks of jute are loosened by mechanical means with a machine of known construction. The loosened j ute-bast is freed by hand or by machinery from the tips and root ends in order to obtain the jute-hast in 2 5 as uniform a state as possible. In the chemical treatment the j ute-bast mechanically treated in the manner above described is first subjected to a macerating process in an alkaline solution and without the aid of heat.

We have discovered in the course of ourexperiments that caustic-soda lyes are most suitable and economical for use in a macerating process. To macerate without the aid of heat, we use, by wayof example, caustic- 3 5 soda lyes havinga specific gravity of 1.035, and we have noticed that the concentration of the macerating-lyes varies according to the quality of the j ute-bast under treatment.

This maceratin g process is carried on in the Q following manner: The jute-hast, out into lengths of about from one to 1.5 meters and freed from root ends and tips, is laid lengthwise in a sheet-iron receptacle having a double perforated bottom and an outlet-cock. 5 Five cubic meters of crude jute-hast may, by

way of example, be placed in such a receptacle. After having thus laid the jute-hast in the reservoir the caustic-soda lyes, of a specific gravity of 1.035, are added thereto-say, for

instance, seven hundred liters (in volume) of such lyes to one hundred kilos of crude jutebast.

To operate with economy-that is to say, to carry on the treatment with the smallest pos sible quantity of caustic-soda lyes'we proceed by successive stages in the following manner, for instance: In the first stage of the macerating process one hundred kilos of crude jute-hast are macerated in seven hundred liters of caustic-soda lyes having a specific gravity of 1.035. In the second stage one hundred kilos of crude j ute-bast are macerated with thelyes expressed and discharged from the first stage with the addition of two hundred liters of fresh caustic-soda lyes of the same specific gravity of 1.035 in order to increase the volume of the said lyes which remains in the one hundred kilos of jute-hast after expression. At the third stage the whole of the lyes expressed and discharged from the second stage, with an addition of two hundred liters of fresh caustic-soda lyes of a specific gravity of 1.035, are used'to increase the volume-z'. e. to economically macerate-according to the indications furnished above, three hundred kilos of crude j ute-bast, which is thus treated by eleven hundred liters instead of by 700x 3:2,100 liters of causticsoda lyes.

The duration of the macerationthat is to say,the time during which the caustic-soda lye is allowed to act on the jute-bast in the receptaole-should amount to about from four to six hours at an ordinary temperature-that is to say, without the aid of heat. After the lapse of this maceration-time of about four to six hours the macerating-lyes are drawn ofi from the receptacle by the discharge-cock and the macerated jute-hast is removed from the said receptacle and freed from the maccrating-lyes which it may still contain by 1 means of. iron cylindrical rollers, the drawn off as well as the expressed lyes from the first stage of the operation being utilized to macerate, with the addition of fresh lyes, as indicated, the jute-hast in the second stage,

which is carried on in the same manner as the first stage. Aftenthe third stage of the macabove that of the jute.

crating process the macerating-lyes are no longer used and are thrown away.

In the chlorin process the jute-hast, macerated in the caustic-soda lyes and freed therefrom by expression, contains about seven per cent. of fixed caustic soda and-is subjected to a chlorin process in achlorin-chamber,preferably made of brickwork lined internally with enameled tiles and provided with a trellis of wooden laths or the like as a support for the macerated j ute-bast, the macer ated and expressed j ute-bast being suspended lengthwise in the chlorin-chamber on the said trellis. As soon as this chlorin-chamber is closed gas-tight and the lead pipe, which starts from the center thereof, has been connected to the chlorin-generating apparatus chlorin-gas is admitted in the said chamber.

According to our experiments one hundred kilos of jute-bast require as much chlorin for the chlorination process as is produced by the mixture of thirty kilos of perox'id of manganese having a yield of from sixty to seventy per cent. of oxygen, sixty kilos of chlorid of sodium, and one hundred and twenty kilos of sulfuric acid at 58 Baum. This chlorin process for the treatment of the macerated jute-hast has for its object to form a compound with the incrustations and in presence of the contents of caustic soda of the macerated and expressed jute-hast submitted according to the indications furnished under the process, as above described, to the chlorin treatment, in particular with the resin jutin discovered by us in the jute-bast, which compound is subsequently entirely re moved in the course of the following cold treatment owing to its being readily dissolved. After having been subjected to the chlorin process the chlorinated jute, which has now an acid reaction, is removed from the chlorinchamber and is washed with cold water in a suitable washing-machine until the washingwater ceases to have an acid reaction, whereupon the washed jute is subjected to a process of revivification. For this purpose the chlorinated and clean-washed jute is transferred to a reservoir of sheet-iron,being placed lengthwise therein. As soon as the jute is placed in the reservoir the chlorinated jute is covered with caustic-soda lyes of a specific gravity of 1.035 until the level of the lyes is One hundred kilos of chlorinated jute-bast require, according to experiments, about four hundred and seventeen liters of caustic-soda lyes of a specific gravity of 1.035 to carry out the revivification process, the lyes being left for about six hours in contact with the chlorinated jute bast. After this time the lyes are removed from the jute-bast and as they are discharged they have assumed, in consequence of the dissolved incrustations, adark reddish-brown color. The

j ute-bast left in the reservoir, which is nowentirely free from incrustations and appears in the form of fine fibers, is washed in the same reservoir with cold water until the washing-water is thoroughly clean and has no alkaline reaction whatsoever. These clean-washed jute fibers are now subjected to a bleaching treatment in a bleaching reservoir made, preferably, of cement and having its bottom covered with a wooden trellis (double bottom) or the like, so that the bleaching-lyes may come through the openin gin the trellis-work uniformly in contact with every portion of the jute fibers thus laid on such trellis. As soon as the jute fibers have been transferred to the bleaching-reservoir the bleaching-lyes are poured thereon in the form of an aqueous solution of a hypochlorite of soda having a specific gravity of 0.5 Baum until the jute fibers are covered over by the same.

,By using hypochlorite of soda as bleaching means for the jute fibers we derive an advantage as compared with the bleaching means hitherto used-that is to say, with a solution of chlorid of lime-in so far that by the use of hypochlorite of soda as bleaching means no lime can adhere to the fibers'. e., no lime particle can become fixed in the intercellular substance of the fibers-whereas in the bleaching of fibers by means of a solution of hypochlorite of lime or chlorid-oflime lyes there was a deposit of lime on the fibers, which could not be removed by a long washing operation and which was the ultimate cause of their brittleness and rigidity. The jute fibers are left in the bleaching-bath from about four to six hours, after which the bleaching-lyes are drawn off from the jute fibers, while the latter are left in the bleaching-reservoir for another two or four hours, so as to be still further bleached. The duration of this further bleaching, as above set forth, is a matter of great importance, as the particles of bleaching-lyes still adhering to the jute fibers (hypochlorite of soda) are re generated by the absorption of oxygen from the air and supply oxygen in a highly oxidizing state (in statu nascemfe) to the jute fibers, which oxygen or ozone acts as a powerful bleaching means, so that this subsequent bleaching permits of fully benefitting by the utilization of the bleaching process.

After the bleaching has been effected ac cording to the indications furnished under the treatments above described the jute fibers are removed from the reservoir and are washed with cold water in a suitable washingmachine until the bleached and washed jute fibers cease to give a chlorin reaction. The bleached and well-washed jute fibers are subsequently drained and dried at a temperature of about 40 centigrade.

The crude jute fibers treated in the manner above indicated appear after being bleached and dried as a fiber, which is entirely free from incrustations or impurities, having a particularly beautiful silky gloss, and when such fibers are spun into yarns and woven into fabrics, either alone or mixed with wool and silk, they make a product hitherto unknown in the textile industries.

' Having now particularly described and ascertained the nature of our said invention and in what manner the same is to be performed, we declare that what we claim is- The herein-described process for the treatment of j ute-bast and the like, consisting in first subjecting the material to mechanical means to loosen the jute and free itfrom tips and root ends; macerating the material thus treated without the aid of heat by subjecting it to caustic-soda lyes; next subjecting the macerated material to pressure to express the lye absorbed by the j ute-bast; next subjecting the macerated material to the action of chlorin gas; washing the chlorinated jute in cold water; subjecting the chlorinated and washed jute to the action of caustic-soda lye; again washing the jute; subjecting the purified and washed material to a bleaching proccess and finally washing and drying the jute 20 Witnesses:

HENRY C. CARPENTER, CHAS. E. CARPENTER. 

